leetcode

commit 631b49f2e2031626a19f7c9e74f1294ed84cb4bb
parent c2b48d325baa1eb01391be3ad89a1f7b5891f94b
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date:   Sun, 29 Sep 2024 11:49:05 +0200

Daily Problem

Diffstat:
A
Problems/0432.cpp
 | 
82
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
README.md
 | 
1
+

2 files changed, 83 insertions(+), 0 deletions(-)
diff --git a/Problems/0432.cpp b/Problems/0432.cpp
@@ -0,0 +1,82 @@
+class AllOne {
+    struct Node {
+        int freq = 0;
+        Node *prev = nullptr;
+        Node *next = nullptr;
+        unordered_set<string> keys;
+    };
+
+    unordered_map<string, Node *> map;
+    Node head = {0, nullptr, &tail};
+    Node tail = {0, &head, nullptr};
+
+  public:
+    void inc(const string &key) {
+        if (map.find(key) != map.end()) {
+            Node *node = map[key];
+            int freq = node->freq;
+            node->keys.erase(key);
+
+            Node *nnode = node->next;
+            if (nnode == &tail || nnode->freq != freq + 1) {
+                map[key] = node->next = nnode->prev = new Node(freq + 1, node, nnode, {key});
+            } else {
+                nnode->keys.insert(key);
+                map[key] = nnode;
+            }
+
+            if (node->keys.empty()) {
+                removeNode(node);
+            }
+        } else {
+            Node *firstNode = head.next;
+            if (firstNode == &tail || firstNode->freq > 1) {
+                map[key] = head.next = firstNode->prev = new Node(1, &head, firstNode, {key});
+            } else {
+                firstNode->keys.insert(key);
+                map[key] = firstNode;
+            }
+        }
+    }
+
+    void dec(const string &key) {
+        if (map.find(key) == map.end()) {
+            return;
+        }
+
+        Node *node = map[key];
+        node->keys.erase(key);
+
+        int freq = node->freq;
+        if (freq == 1) {
+            map.erase(key);
+        } else {
+            Node *pnode = node->prev;
+            if (pnode == &head || pnode->freq != freq - 1) {
+                map[key] = pnode->next = node->prev = new Node(freq - 1, pnode, node, {key});
+            } else {
+                pnode->keys.insert(key);
+                map[key] = pnode;
+            }
+        }
+
+        if (node->keys.empty()) {
+            removeNode(node);
+        }
+    }
+
+    string getMaxKey() const { return tail.prev == &head ? "" : *(tail.prev->keys.begin()); }
+
+    string getMinKey() const { return head.next == &tail ? "" : *(head.next->keys.begin()); }
+
+  private:
+    void removeNode(Node *node) {
+        Node *pnode = node->prev;
+        Node *nnode = node->next;
+
+        pnode->next = nnode;
+        nnode->prev = pnode;
+
+        delete node;
+    }
+};
diff --git a/README.md b/README.md
@@ -329,6 +329,7 @@ for solving problems.
 |  0427  |   Medium   | [Construct Quad Tree](Problems/0427.cpp)                                                           |
 |  0429  |   Medium   | [N-ary Tree Level Order Traversal](Problems/0429.cpp)                                              |
 |  0430  |   Medium   | [Flatten a Multilevel Doubly Linked list](Problems/0430.cpp)                                       |
+|  0432  |    Hard    | [All O`one Data Structure](Problems/0432.cpp)                                                      |
 |  0433  |   Medium   | [Minimum Genetic Mutation](Problems/0433.cpp)                                                      |
 |  0435  |   Medium   | [Non-overlapping Intervals](Problems/0435.cpp)                                                     |
 |  0436  |   Medium   | [Find Right Interval](Problems/0436.cpp)                                                           |